Summary

This review collected studies up to September 2023 on testosterone or oestrogen for teens and young adults with gender distress, and rated the evidence. Of 24 studies, none was a randomised trial, where people are assigned to treatment by chance. Most ignored other mental health care, family support or missing results. Almost every finding on mental health and gender distress was rated very low quality. One study linked hormones to somewhat less depression, but this too was weak evidence. In one study, about 4% of females on testosterone had a heart or blood vessel event over several years. With no comparison group, this cannot show the hormones caused them. The authors conclude benefit or harm cannot be ruled out. The findings match other reviews, but the review was commissioned and paid for by SEGM, a group critical of youth transition, and newer studies are not included.

Key findings

• レビューでは、平均年齢26歳未満の人々への異性ホルモンに関する24件の研究が見つかりました。9件は治療を受けた人と受けていない人を比較し、13件は前後で測定し、2件は治療を受けた患者を記述しただけでした。
• 人々が偶然によって治療に割り当てられる無作為化試験はありませんでした。
• 性別への苦痛、日常の機能、うつ病に関するエビデンスは、大半が非常に低い品質と評価されました。
• 1件の研究では、ホルモンを使った人はうつ病になる可能性がやや低いことが分かりました（オッズが約4分の1低い）が、これは低品質のエビデンスと評価されました。
• ある記録の研究では、女性3,875人のうち151人（3.9%）が、テストステロン開始の7か月から9年後の間に心臓または血管の事象を経験しました。別の研究では、約2年後に1,893人中3人（0.2%）でした。
• ある研究では、315人中2人（0.6%）が2年以内に自殺で亡くなりましたが、このエビデンスは非常に弱いと評価されました。
• 多くの研究は、精神科の治療、他のメンタルヘルスの状態、収入、家族の支援を考慮しておらず、いくつかの研究では人々の半数未満の結果しか得られていませんでした。
• 著者らは、利益も害も除外できないと結論づけ、人々を時間の経過とともに追跡する慎重な研究を求めています。

Abstract

Objective In this systematic review and meta-analysis, we assessed and summarised the certainty of the evidence about the effects of gender affirming hormone therapy (GAHT) in individuals with gender dysphoria (GD). Methods We searched Medline, Embase, PsychINFO, Social Sciences Abstracts, LGBTQ+ Source and Sociological Abstracts from inception to September 2023. We included studies comparing GAHT with no GAHT in individuals aged <26 years with GD. Outcomes of interest included psychological and physical effects. Pairs of reviewers independently screened articles, abstracted data and assessed the risk of bias in the included studies. We performed meta-analyses and assessed the certainty of the evidence using the grading of recommendations assessment, development and evaluation (GRADE) approach. Results We included 24 studies. Comparative observational studies (n=9) provided mostly very low certainty evidence regarding GD, global function and depression. One comparative observational study reported that the odds of depression may be lower (OR 0.73 (95% CI 0.61 to 0.88), n (number of studies)=1, low certainty) in individuals who received GAHT compared with those who did not. Before-after studies (n=13) provided very low certainty evidence about GD, global function, depression and bone mineral density. Case series studies (n=2) provided high certainty evidence that the proportion of individuals with cardiovascular events 7-109 months after receiving GAHT was 0.04 (95% CI 0.03 to 0.05, n=1, high certainty). Conclusion There is considerable uncertainty about the effects of GAHT and we cannot exclude the possibility of benefit or harm. Methodologically rigorous prospective studies are needed to produce higher certainty evidence. Trial registration number PROSPERO CRD42023452171.

Conclusion

The best available evidence reporting on the effects of GAHT in individuals with GD ranged from moderate to high certainty for cardiovascular events and low to very low certainty for the outcomes of GD, global function, depression, sexual dysfunction, BMD and death by suicide. We did not find evidence of sexual dysfunction in NMs. The evidence in this SR and meta-analysis does not exclude the possibility of benefit or harm upon receipt of GAHT. Prospective studies giving higher certainty evidence are needed to understand the short and long term effects of GAHT.